The Audemars Piguet Royal Oak “Jumbo” Extra-Thin Selfwinding Flying Tourbillon Chronograph RD#5 (Ref. 26545XT.OO.1240XT.01) was unveiled in October 2025 as the final timepiece in the brand’s Research and Development (RD) series.

Released to coincide with Audemars Piguet’s 150th anniversary, the Royal Oak “Jumbo” Extra-Thin Self-Winding Flying Tourbillon Chronograph RD#5 is a limited-edition model that redefines the traditional chronograph mechanism while preserving the classic 39 mm x 8.1 mm Royal Oak “Jumbo” aesthetic and proportions. The case is constructed from lightweight titanium, while the bezel, pushers, and links in the bracelet are crafted from Bulk Metallic Glass (BMG), a durable, scratch-resistant palladium-based alloy.

The “Bleu Nuit, Nuage 50” dial features a Petite Tapisserie pattern with two sunken chronograph sub-dials at 3 and 9 o’clock, trimmed with metal rings, with a flying tourbillon visible through an aperture at 6 o’clock. The dial features 18K white gold luminescent bathtub hands and hour-markers, a silver grey-toned inner bezel, and the “Audemars Piguet” signature inspired by historical documents at 12 o’clock. A function-selector crown replaces the traditional pull-out stem for winding and setting the time.

Inside is the new caliber 8100, a 3Hz automatic flyback chronograph with a flying tourbillon. The chronograph reset mechanism uses an innovative rack-and-pinion system that replaces the traditional hammer-and-cam architecture, resulting in pushers that require significantly less force to operate. This allows for an exceptionally light and smooth pusher feel, similar to that of a smartphone button, according to Audemars Piguet.

The 44-jewel, 379-component, automatic chronograph movement resembles a hand-wound movement, thanks to a slim peripheral rotor that automatically powers the watch’s 72-hour power reserve, based on motion in the same way a traditonal rotor does. The design also allowed Giulio Papi and his development team to fit a flyback chronograph and flying tourbillon in a svelte 31.4 mm x 4 mm footprint. This chronograph, which utilizes a column wheel and redesigned vertical clutch system, features a more ergonomic and precise chronograph reset/flyback function, and also offers an instantaneous chronograph minute change.

The Royal Oak “Jumbo” Extra-Thin Flying Tourbillon Chronograph RD#5 (Ref. 26545XT.OO.1240XT.01) is not technically considered water-resistant, with a rating of just 20 meters. The Royal Oak RD#5 150th Anniversary is limited to a run of 150 individually numbered pieces and is available exclusively through Audemars Piguet boutiques for around $325,000 (CHF 260,000).